1. Technical Field
Aspects of the present invention relate to an image forming device.
2. Related Art
As an example of an image forming device, a device in which photosensitive drums respectively corresponding to yellow, magenta, cyan and black are arranged is known. In this configuration, on outer surfaces of the photosensitive drums, toner images are respectively formed. There is a case where a toner remains on the outer surface of the photosensitive drum. For this reason, for each of the photosensitive drums, a recovering member which recovers the toner remaining on the outer surface of the photosensitive drum is provided in the image forming device. During image formation, a recovering bias is supplied to the recovering member. By the effect of the recovering bias, the toner remaining on the outer surface of the photosensitive drum is transferred to the recovering member, and is held tentatively on the recovering member.
By executing a toner transfer process (a cleaning process) at a predetermined timing, the toner held on the recovering member is recovered by a cleaning unit via the photosensitive drum and a carrying belt. In the toner transfer process, a bias whose polarity is opposite to the recovering bias is supplied to the recovering member. In addition, a bias whose polarity is the same as that of a transfer bias is supplied to each transfer roller. By the effect of the bias supplied to the recovering member, the toner held on the recovering member is returned to the outer surface of the photosensitive drum. Then, by the effect of the bias supplied to each transfer roller, the toner returned to the outer surface of the photosensitive drum is transferred to the carrying belt. The toner transferred to the carrying belt is recovered into the cleaning unit when the toner faces the cleaning unit.